1. Field of the Invention
The present invention relates to an inkjet recording apparatus using a line-type recording head.
2. Description of the Related Art
A line-type inkjet recording apparatus uses a line-type recording head in which a nozzle array extends over the entire width of a recording region. In a nozzle that is not frequently used in the nozzle array, a volatile component of ink evaporates, and this increases the ink viscosity. If the increase in ink viscosity further continues, there may be a risk that the nozzle cannot discharge ink.
To overcome this problem, attempts have been made to suppress evaporation of the volatile component of ink by supplying humidified gas near the nozzles in the recording head for the purpose of moisture retention. For example, Japanese Patent Laid-Open No. 2006-44021 (Patent Document 1) discloses a recording apparatus having a structure for supplying humidified gas into a gap between a recording head and a sheet.
To reduce the unevenness in use frequency of nozzles included in a nozzle array of a line-type recording head so that the total durability of the nozzles increases, it is effective to move the recording head relative to a sheet in the extending direction of the nozzle array at regular intervals.
When the nozzle array is moved, the position of the nozzle array relative to a flow of humidified gas changes, and this may hinder proper humidification at ends of the nozzle array. However, if a large amount of humidified gas is supplied to a wide area in consideration of the movement of the nozzle array, waste increases and the use efficiency of the humidified gas decreases. Patent Document 1 described above does not take this problem into consideration.